TIFF alpha channel glows on edges
With image packaged into blend it works for me as expected. The issue appears when TIFF is unpacked and used linked from directory. Troy_s probably will be able to explain the issue, I don't have a knowledge in this area. I can just say how to avoid the issue here.


your TIFF doesn't use Transparency but channel &quot;Alpha&quot; (that is also why option &quot;Save Transparency&quot; is grey when you are saving your TIFF



to avoid the issue copy alpha channel and paste into Mask channel for &quot;Background&quot; layer.



Then when you save with &quot;Layers&quot;, &quot;Save Transparency&quot; is available.



This TIFF is rendered fine in Blender.